Fluid-pressure valve



J. DAVIDSON.

FLUID PRESSURE VALVE.

7 APPLICATION F ILED FEB. 24, I916. 1,350,438. P en egAug. 24,1920.

awucmtoz PATENT QFFlCE.

aosnric DAVIDSON, or EAST POINT, GEORGIA.

FLUID-PRESSURE VALVE.

Specification of Letters Patent.

Application filed February 24, 1915. Serial No. 80,240.

To all whom it may concern:

Be it known that I, JOSEPH DAVIDSON,- a citizen of the United States,and resident of East Point, county of Fulton, and State of Georgia, haveinvented an Improvement in Fluid-Pressure Valves, of which the followingis a specification.

The object of my invention is to provide a construction of valvesuitable for hydraulic machinery which shall have capacity for acting asa supply and relief valve or for a three-port control with a singlemovable plunger structure irrespective of the special uses to which itmay be put. I

()nc useto which my improved hydraulic valve is well adapted is set outin my application Ser. No. 71,840, filed January 13, 1916, for machinefor forming oil-cakes, in which my improved valve construction isemployed for controlling the fluid pressure to the hydraulic cylinder ofthe plunger operating the meal tray, and also in the control of thefluid pressure to and from the operating motor for the head tree.

My improved hydraulic valve embodies in its construction, a body havinga straight passage through its length, said passageway having acontracted central ortlon having oppositely arranged seats a its ends,and

further having side openings or ports, one opening into the passagebetween the seats and the others respectively opening into the passagebeyond the seats, said body associated with a plunger valve structure ofgreater length than the body and filling the larger bores of thepassageway, and further having a central smaller cross section ofgreater length than the distance between the seats and provided withannular valve seat ing portions adapted to the respective seats, theproportions being such that when one valve seating portion is seated theother valve seating portion is beyond the port beyond the othervalveseat and vice versa, and suitable stuflingboxes on the opposite ends ofthe body for providing fluid tight packing.

lVith the above and other objects in view, the nature of which will bemore fully understood from the description hereinafter, the inventonconsists in the novel construction of hydraulic valve as hereinaftermore fully described and defined in the claims,

Referring to the drawings :Figure 1 is an elevation of my improvedhydraulic valve with the supply and relief pipes in section; Fig. 2 is avertical sectional view of the same taken on line 7 3/ of Fig. 1, butwith the plunger structure in elevation; and Fig. 3 is a cross sectionof same taken on line ax of Fig. 2.

2 is the body and is preferably made from a solid block of steelsuitably bored and drilled and otherwise shaped as shown. This body 2provided with a through pas sage comprisin the parts 3, 8 and 5 inalinement and having the smaller diameter of the part 8 opening into thelarger diametered portions 3 and 5 through the respective valve seats aand 7. Furthermore, the larger bore 3 is formed with an annular groovedportion 12 having a side port 13 by which fluid pressure may be suppliedfrom a pipe 25. Similarly, the larger bore 5 is formed with an annulargrooved portion 10 having a side port 11 by which the fluid pressure maybe released to the relief pipe 27. Moreover, the smaller bore 8 ispreferably pro- "idQCl with an annular grooved portion 8 having alateral port 9 with which a pipe 9 may connect, said pipe adapted toprovide communication with a hydraulic or other machine to which fluidpressure is required to be supplied under control. In the preferredconstruction, the distance between the seat 7 and port 13 issubstantially equal to the distance between seat l and port 11, but thisis not essential.

The plunger structure adapted for operation with the above describedbody, comprises two plunger portions 1% and 18 connected by the smalleror neck portion 16 with which they connect through the valve seatseatingportions 15 and 20 are preferably conical and are oppositely directed asPatented Aug. 24, 1920.

- ing portions 15 and 20 respectively. These ing the plunger structurewithin the body.

To provide a fluid tight valve, the opposite ends of the body arerespectively furnished with hydraulic annular packing 21 and 23 andbushings 22 and 24 by which the plunger portions 14 and 18 are tightlypacked and also supported, said bushings acting as guides for theplunger portions, as will be readily understood by reference to Fig. 2.

\Vhile the supply pipe 25 and the relief pipe 27 maybe attached to thebody in any suitable'manner, such as in the case of pipe 9 for example,I have shown a suitable union joint for said pipes for more convenientlycoupling them, and especially where it is not convenient to rotate thepipes because of their connection with other parts of the apparatus. Inthis particular construction, the pipe 25 has a tapered end 26 which itsthe tapered port 13, and similarly, the pipe 27 has a tapered end 28which fits the tapered port 11. Furthermore, both of these pipes 25 and27 have collars 29. Extending about the pipes 25 and 27 and pressingupon the collars is a plate 30 which may be drawn toward the body 2 bymeans of the cap screws 31. In this manner the pipes may be clampedtightly into position in the body or may be readily disconnected in caseof repairs.

The operation of the valve may be described as follows :Assuming thatthe parts are in the position shown in Fig. 2, it is manifest that anyfiuid pressure which may have existed in the device being operated willbe relieved through pipe 9, passage 8, passage 5, port 11, to the reliefpipe 27.

source which would be delivered by the pipe 25 is shut off by the valveseating portion 15 of the plunger 14, which tightly rests upon the valveseat 4. It will also be seen that the plunger 14 substantially fills thepassage 13 and shuts off the free supply of the fluid from the port 13and annular grooved portion 12 from finding its way to the valve seat,so that there is a double shutting off of the fluid pressure from thepassage 8 and pipe 9. Assuming now that it is desired to supply fluidpressure to the device to be operated, the plunger structure is raiseduntil the seating portion 20 of the plunger 18 seats upon the valve seat7 of the passage 15, and this effectually closes communication with therelief pipe 27; and the plunger 18 completely fills the passage It willalso he observed that the fluid pressure from the accumulator or othertion due to the high fluid pressure.

5 and shuts off the annular. grooved portion or chamber 10 and its port11 from communication with the valve seat, thereby insuring a morepositive sealing of the relief. WVhile this is being done, the plunger14 has risen sufficiently to carry the valve seat- ,ing portion 15 abovethe annular grooved or chamber portion 12 and port 13, so that the fluidpressure may then pass freely through the passage 3, valve seat 4,passage 8, and into the pipe 9 which communicates with the device to beoperated. It will be noted that one of the valve seating portionsrespectively seats upon its valvev seat, just as the other valve seatingportion has passed to the limit of its movement in opening the supply orrelief pipe communication, as the case may be, and it will further beobserved that during the shifting of the plunger structure there will bea time when both of the valve seating portions 15 and 20are off theirseats 4 and 7, and it is at this time that the bodies of the plungers 14and 1S fitting the respective passages 3 and 5 act as cylinder valves toprevent supply or escape of fluid pressure. It will therefore be seenthat the valves, and second, as plunger valves assisted by conical valveseating portion The reason for the combination of the two parts forcontrolling the fluid pressure is that the cylindrical or plungerportions need not be so tight as would be required if the conicalseating portions were not employed. On account of the valve shiftingwith reasonable speed, any slight leakage around the plungers would notbe harmful provided the valve were tight when fully shifted, and this isinsured by the conical seating portions 15 and 20 cooperating with theannular conical seats 4 and 7.

Another feature'of the valve is the employment of the annular grooved orchamber portions 10 and 12 which communicate with the lateral ports'lland 13 respectively. By means of these annular chambers the flow offluid pressure is supplied more uniformly through the passage, isquicker in action, and provides a thorough balancing of the pressureabout the plunger portions which could not otherwise be secured if thelateral ports opened directly against the plungers. In this Way theplunger structure is thoroughly balanced and free from undue fric As theplungers 14 and 18 are the same in diameter, it is manifest that thevalve is a balanced valve, whether in supplying pressure or in relievingit, and as the annular passages 10 and 12 extend wholly about theplungers, it is evident that no variation in pressures can affect thefreedom of movement of the plungers themselves. 7

While the annular chambers 10 and 12 are especially important inconnection with the valves are double acting. First, as plunger ports 11and 13, it is not so important that there shall be an annular portionformed in the central passage 8', as this passage is of considerablygreater diameter than the neck portions 16 of the plunger structure; butas it is desirable to have as free passage for the fluid pressure aspossible to all sides of the plunger structure, I preferably engage thesaid passage 8 in alinement with the lateral port 8, as clearly shown.

It will also be observed that while I prefer to make the plungerstructure in two parts secured together by the bolt 19, it is manifestthat the same construction shown in connection with the plunger 18 mightbe employed also in respect to the plunger 14, the manner of assemblingthe parts permitting the plungers to be entered from opposite ends ofthe body and coupled for use. In the construction shown, it is also seenthat the operative part of the plunger is continuous from one end to theother, and this is desirable on account of the strength. I, however, donot restrict myself in these details.

It will now be apparent that I have devised a novel and usefulconstruction which embodies the features of advantage enumerated asdesirable, and while I have in the present instance shown and describedthe preferred embodiment thereof which has been found in practice togive satisfactory and reliable results, it is to be understood that I donot re strict myself to the details, as the same are susceptible ofmodification in various particulars without departing from the spirit orscope of the invention.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In a fluid pressure valve, a body part having a through passagecomprising two end portions of uniform diameters separated by oppositelydirected valve seat portions arranged at a distance apart and alsohaving a port opening from the passage between the valve seats andfurther having separate additional ports opening from the side walls ofthe end portions of the passages at a distance from the respective valveseats and respectively terminating in annular chambers surrounding andopening into said passages, combined with a plunger structure of greaterlength than the body part and comprising two plunger portions of uniformdiameters respectively closely fitting the end portions of the passageso as to be surrounded by the annular chambers and connected by a neckportion of less cross sectional area than the passage between the valveseats, and which plungers adj aeent to the neck portion are providedwith seating portions adapted to the valve seats but arranged at adistance apart greater than the distance between the valve seats andless than the distance between passages of the body part, and suitablepacking means surrounding each of the end portions of the plunger andfitting the opposite ends of the body part, whereby each end of theplunger structure is exposed beyond the body.

2. In a fluid pressure valve, a body part having a through passagecomprising two end portions of uniform diameters separated by oppositelydirected valve seat portions arranged at a distance apart and alsohaving a port opening from the passage between the valve seats andfurther having separate additional ports opening from the side walls ofthe end portions of the passages at a distance from the respective valveseats, combined with a plunger structure comprising two plunger portionsof uniform diameters respectively closely fitting the end portions ofthe passage and connected by a neck portion of less cross sectional areathan the passage between the valve seats, and which plungers adjacent tothe neck portion are provided with seating portions adapted to the valveseats but arranged at a distance apart greater than the distance betweenthe valve seats and less than the distance between the additional portsentering the sides of the end portions of the passage in which theplungers operate, said plunger structure having one of its plungersprovided with a neck and a shank of smaller diameter extending from saidneck upon which the other plunger is sleeved and clamped thereon infixed spaced relation from the other plunger.

8. In a fluid pressure valve, the combination of a body having a throughpassage, consisting of two bores in alinement of substantially the samediameter and separated by oppositely directed valve seats, and alsohaving a lateral port from the passage between the valve seats andadditional inde pendent lateral ports opening from the sides of thebores of the same diameter at a distance from the respective valveseats, and in which each of said independent lateral ports providescommunication with the here by an annular chamber extendingsubstantially around the bore, a plunger structure comprising twoplunger portions of uniform diameters each snugly fitting the respectivebores of the same diameter and connected by a neck portion of less crosssectional area than the cross sectional area of the passage through thevalve seats and the passage between said seats, said plungers extendingbeyond each of the bores and provided with oppositely directed seatingportions for the valve seats and in which said seating portions areseparated a distance greater than the distance between the valve seatsand less than the distance between the independent In testimony of whichinvention I herelateifitl ports entering the passages occupied unto setmy hand.

by t e plungers, and suitable acking means surrounding each of the plung'ers and fitting JOSEPH DAVIDSON the opposite ends of the body wherebyeach Witnesses:

end of the plunger structure is exposed be E. W, SMITH, I

yond the body. i C. E. KLEINFELDER.

